Recently saving energy is considered in various fields in view of preventing global warming. Progress has been made in the energy saving such as less power during stand-by time, and consideration of the low temperature fixing of the fixing process consuming most energy in the information apparatus such as an image forming apparatus.
There is a problem that the toner must be composed of a resin having high glass transition temperature to obtain storage durability against heat in the toner having basic structure and therefore the fixing temperature is inevitably high, fundamentally. Consequently the storage durability against heat and low temperature fixing ability are in a trade-off relation and it is difficult to compatibly attain.
A toner is proposed which contains cross-linking a resin obtained by bonding a polymer containing carboxylic acid component and a multi-valent metal compound for a toner of the electrophotographic image forming apparatus to realize low temperature fixing, as disclosed in, for example, JP-B H08-003665. Low temperature fixing ability and storage durability against heat can be obtained compatibly since melt viscosity of the resin lowers due to cleavage of bond relating to cross-liking by heating at thermal fixing process.
However, fixing temperature requires at lowest 150° C., and therefore sufficient low temperature fixing cannot be obtained by employing the proposed resin.